Plastic-board manufacture



Se t. 2, 1930. H. c. RAYNES PLASTIC BOARD MANUFACTURE- Filed Nov. 1, 1926 2 Sheets-Sheet 1 I Harry 8. Ray fi ymw ww iy I 'fltt Sept. 2, 1930. H. c.. RAYNES PLASTIC BOARD MANUFACTURE 2 Sheets-Shout 2 Filed Nov. 1, 1926 Patented Sept. 2, 1930 V'FPAVTENT OFFICE HARRY c. HAYNES, oi roarsmou'rn, NEW naivirsnmnynssienoa, BY MESHE AB- SIGNMENTS, '10 IBEMIS INDUSTRIES, INCORPORATED, OI BOSTON,

A coarona'rron or DELAWARE mssacnusarrs.

rmsrrc noaan MANUFAG'IIUBE Application filed November The present invention reigtes to the making of wall board for buildi g purposes, and moreparticularly disclosesan apparatus and method for manufacturingwall board with a frangible or cementitiouscore or body portion which is bound in and reinforced by a fibrous covering of paper or the like.

The present inventio'n pertains more particularly tothe making of such a board so that the fibrous covering is formed-in a sub stantially integral sheath'about an elongate slab which continuously issues from the machine and may be cut into suitable lengths. Inproviding-for the making of a wall board of this character the principles of the, Fourdrinier and cylinder mold paper achins are combined with components of he ordinary apparatus for making wall boards, plaster or the like, whereby iormation'and 3S1 sembly of the wall board may take place in a continuous operatiomand in one combination of /machines.

. It is thus possible to provide a-wall boardwhich-is similarto that disclosed in my co,- pend ng application. Serial No. 131,661, filed August 26, 1926, or may be of the form co'm-.

monly associatedwith plaster boards which are bou y. paper or thelike, with the ex ception that the fibrousenvelope' or sheath which surrounds the core of the plaster board i made by the present process may be substantially integral and the paper-or fibrous coattion wi which ing mavbeunited with the plastic core by an unusually strong interlocking bond. With these'general'object's in viewit will appear from the following description that. the process and apparatus may be varied'in ways to suit various materials used and-to.

provide various resulting. types of wall The above andfurtlier objects and advan- .tages of. the invention will be a mntm "those skilled in the art upon, a l-reading oitlie Fig. :1,is" 'a di g mmatic sectional view it of -the;apparatus ,for making .the improved 0 wall boar difierentl P p r to such subjoined description and claims inconjunca p h the accompanyingdrawings, in

1, 1926.. Serialilio. 145,485.

Fig. 2-is a perspective view of a portion of the wall board Fig. 3 is a section on line 3 -3 of Fig. 1; Fig. 4 is a section on line 4+4 of Fig. 1;

' Fighfi is a section on line 5 5 of Fig. 1'; Fig. 6 is a section on line 6.-6 of Fig. 1,

and

Fig. 7 is a section on line T -7 of Fig. 1.

central core or body portion of frangible or cementitious material, such as gypsum, preferably calcined; and having, if desired, a suitable fibrous aggregate combined therewith, it is proposed, in accordance with the v In order to provide a fibrous. layer or the wall board, which,

coating for one. side 3f will-be the lower si e, asthe board is produced in the machine, apparatus of the gen- .eral type associated with the conventional Fourdrinier machine is providedand is diagrammatically illustrated at the left of Fig.

1' and designated by the numeral 1. A flow box 3-is adapted to supply pulp composed of any suitable fibrous material "liquid prepared wood-fibers combined with ground a proportion as is suitable for making heavy wrapping paper, chipashredded wood fibers mixed ton fibrous, or similar substances.

or felt 7 and is drawnthrough a suitable series o'frolls 4 and passes through drying box '5. The rolls and drying 'box, as disclosed in Fig. 3, have a width lessthan that oflthe belt. 7 which supports the pulp so that and dried to a. much greater extent than'the loose edge portions 8 eated next tothe deckels 9.

the inter- In order to providea wall board having a such as water, .for instance, suitablyt'h of which are 10- suspended ina or minute a with cote" 9c This fibrous materlal 2 passes upon a wire the ii di t"pprtion of the pulp isipressed mediate portion of the pulp has thus been rial comes from an elevated hopper which is adapted to contain-comminuted gypsum with or without an aggregate and with either an accelerator or decelerator to aid or retard drying, ifdesired. The plastic material falls upon a moving belt 13 which dips into a'vat 14 where the gypsum is hydrated and from which it passes under slices 16 which control the thickness of the gypsum layer and thence drops over the roll 17 upon the moving pulp layer 2. Suitable press rolls 19., Fig. 3, compact the gypsum upon the intermediate portion of the moving. pulp and tend to press the loose edge portions thereof out- ;lrvardly against the deckels 9, as disclosed in After the gypsum or the like. has been suitably compressed and somewhat dried, the

.upper layer of fibrous material is introduced from an elevated source of pulp, designated in general by the numeral 21, and comprising a suitable number of rolls combined with a conveying belt 22 adapted to bring the upper.

layer 24 of fibrous material upon the gypsum and pulp. A suitable series of rolls 23,. Fig; 5, is provided to press the upper layer of fibrous material upon the gypsum and upon the undried pulp at either side, thus eflfecting in variousstages partial dehydrating of the masses of pulp at either side of the gypsum and the upper layer of pulp, and causing still further drying of the lower layer of pulp; it being obviousthat the amount of water which is drawn from the upper layer and the marginal masses of the pulp will be much greaterthan that which is forced from the lower layer of pulp during this part of the process. I

It may be further observed that the upper layer of fibrous material is deposited upon the main body of moving material with- Y out passing through a drying box, so that the marginal masses of pulp andthe upper layer; of pulp have substatially the same water content and may be readily forced into-an intimate bonded relation to comprise a substantially integral continuous layer about the intermediate gypsum mass. Also it will be I evident that there will be no sharp line of demarkation between the marginal masses and the-bottom layer of fibrous ulp so that the marginal masses and the bottom and top layers will both be substantially integral and continuous and there vwill be no sharply defined zones in which the percentages of water are radically'difl'erent. After the upper'and lower layers have thusv been pressed upon opposite sides of the intermediate gypsum layer, suitable press rolls 32 at either side of the moving material are adapted to effect transverse compression, pressing the pulp mass against the gypsum core and providing both that core and the fibrous material with substantially square edges, Fig. 6. These rolls may preferably be arranged in conjunction with upper and lower rolls 36,

in order to compress the moving mass upon all sides. After having passed through a suitable series of rolls of this character the material, which has 'now-sufiiciently dried,.is passed between a pair of saws 35 which are adapted to trim the edges 8of the fibrous desirable to permit the marginal portions of the plaster board to remain covered with a fibrous layer which is considerably thicker than the fibrous covering upon the faces "of the board. A board of this type will be simi-' lar to that disclosed in my above-identified c'opending application and will have fibrous marginal portions'upon either side sufficient 1y wide to permit the ready nailingthereof' when the plaster board is located upon a wall or ceiling, as more particularly described in said application.

Leaving the saws, the. wall board passes in a continuous strip upon suitable conveyor rolls from which it may be removed in suitably cut sections, and after which it is further dried'to provide the type of wall board disclosed in Fig. 2, which comprises an intermediate slab of frangible material pref- 'erably having a base of calcined gypsum 33 which may be mixed with suitable aggregate and a substantially continuous sheath or binding of fibrous material 43. Obviouslyv wall board of this character will be unusually strong due to the lack of joints or seams in the fibrous covering and due to the firm bond between the fibrous and plastic material resulting from the concomitant forming and drying of these substances in intimate contact with one another. I

I claim:

1. The process of making wall board- Which comprises concomitantly forming a frangible core and an'outer sheet of fibrous material thereon, .by providing a moving layer of hydrated fibrous pulp with marginal masses of pulp at either side of the layer of greater thickness than the intermediate portion thereof, placing a layer of hydrated cementitious material upon the intermediate ortion of the pulp layer, and concomitanty drying the materials and pressing them into intimate engagement.

2. The process of making wall board which comprises providing a lower continuously moving layer of fibrous material and marginal masses of hydrated pulp at either side of the fibrous layer,-locating a mass of hydrated plastic material upon the fibrous macbmpacting of the hydrated fibrous material and plastic.

3. The process of making wall board which comprisesjproviding a lower continuv i d marg1 1 al masses above the plastic and said -masses, and compressing the resultingcomblously moying layer of fibrous material an marginal masses of hydrated pulp at either side of the fibrous layer,ilocating a mass of hydrated plastic material upon the fibrous material between the marginal masses, bringing an upper layer of hydrated fibrous material upon the marginal masses and the plastic material, and efl'ecting the concomitant drylngjand fibrous material and plastic. 7

4'. The process of making fiberboard which comprises locatin a hydrated intermediate layer of plastic terial within an outer surrounding layer of hydrated fibrous material, making said outer layer continuous about the intermediate layer, and effecting the concomitant drying and compacting of the layers into intimate union. Y Y

5. The process of making fiber board which comprises locating a hydrated intermediate layer of plastic material within an outer layer of hydrated mate'riaLmaking said outer layer continuous about the intermediate layer, adjoining portions of which have similar moisturec'ontents, and efiecting the concomitant drying and compacting of the layers into intiinate union,-

'. 6Q The process of making wall board which comprises PIOVldlIlg a lower moving layer of hydrated cellulose fibers, partially dehydrating 'the same, providing marginal masses of similar material which retain a larger percentage of liquid,.bringin'g an in-' termediate stream of (plastic material upon the lower layer and between the marginal masses, locating an upper layer of fibrous material having a moisture content similar to that of the marginal masses above the 'plastic and'said masses, and -concom tantly'drying and" compacting the resulting combina tion; a

7. The process of making'wall b vard which comprises providing a' lower moving layer of hydrated cellulose fibers, partially dehydrating andcompressing the central portion of the layer while-leaving marginal masses with substantially their original thickness and liquid',.content,bringing an intermediate stream of plastic, material upon the lower layer and between the marginal masses-, lo-\ eating an upper layerof fibrous materialxhaving a moisture content, similar to that of the marginal masses above 'the plastic and said masses, and concomitantly drying and compacting the resulting combination. J

8; The process of making wall board which comprises providing a lower moving layer of I hydrated lng an upper compacting of the hydratedsuperposed upon the cellulose fibers, partially dehydrating the same and providing marginal masses of similar material which retain a larger percentage of liquid, bringing an intermediate stream of plastic material upon the lower layer and between the marginal masses, locating a moisture content similar to that of the nation both transversely and vertically; L I

layer of fibrous material hav-' 9. The process of making wall board which I comprises "providing a lower moving layer of hydrated cellulose fibers, partially dehy- 'drating-and compressing the central portion of the layer, while leaving marginal masses with substantially their original thickness and liquid content, bringing an intermediate stream of plastic material upon the lower layer and between the marginal masses, loeating-an upper layer of fibrous material having a moisture content similar to that of the marginal masses-above the plastic and 'said masses, and compressing the resulting combination both transversely-and vertlca ly.

10. The process of making wall board which comprises providing a lower moving layer of hydrated cellulose fibers partially d hydrating the same, providing marginal masses of similar material but retalning a larger percentage of liquid, bringing an in; 'termediate stream of plastic material upon the lower layer and between the marginal masses, compressing the plastic upon .the

' lower layeriof fibrous material to effect partial dehydration of the same, locating an upper layer of fibrous material having a moisturecontent similar to that of the marginal masses abo Ve the plastic. and said masses, and

concomitantly dryingand compacting the re-' sulting combinatlon.

11-. Wall board comprising a frangible slab and an uninterrupted,= continuous fibrouscovering about the same, said covering being free from joints or seams.

1-12. The process of making wall board which comprises providing a lower continuously moving layer of hydrated pulp" and marginal masses of hydrated pulp at either side of the layer of hydrated pulp, which are margins of the pulp layer, locating a mass of hydrated plastic material upon the hydrated pulp layer between the marginal masses, bringing anuppe'r layer of fibrous material upon the marginal masses and the plastic material, and efliectingthe concomitant drying and compacting of the hydrated fibrous material and the plastic material.

- 13. The process of making wall board which comprises providing a lower continuously moving layer of 'hydratedpulp and "similar marginal masses of hydrated pulp at either. side of the la er of hydratedpulp,

the pulp 1ayer, lacating a mass of hydrated lastic material upon the hydrated pulp layer lietween. the marginal masses, bringing an upper layer of hydrated pulp upon the mar- 5 ginal masses and the plastic material, and

efi'ecting the concomitant drying and compacting of the hydrated fibrous material and the plastic material.

Signed by me at Portsmouth, New Hamp- 1O shire this twenty-eighth day of October,=1926.

. HARRY G. RAYNES. 

